JPS595138B2 - Acrylonitrile resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas-impermeable acrylonitrile resin composition for molding that has excellent alcohol resistance, impact resistance, transparency, color tone, and processability.

In recent years, molding acrylonitrile resins containing high acrylonitrile have gas impermeability, water vapor impermeability, and impact resistance, so they have been used for food packaging films, carbonated beverages, alcoholic beverages, foods, It is becoming widely used in cosmetic containers and the like.

Such acrylonitrile-based resins include acrylic acid alkyl esters or methacrylic acid alkyl esters having 70% by weight or more of acrylonitrile and an alkyl group with a small number of carbon atoms (1 to 6 carbon atoms) in the presence of a diene-based rubbery polymer. A graft obtained by mixing a graft copolymer obtained by graft polymerizing a monomer mixture consisting of 30% by weight or less of at least one of the above with a resinous polymer obtained by copolymerizing the monomer mixture. - Blend type resin compositions (for example, Japanese Patent Publication No. 49-13853) are known.

In addition, a similar graft-blend type resin composition is disclosed in Japanese Patent Application Laid-open No. 4
8-791. However, the graft-blend acrylonitrile resins produced by these methods have poor water resistance and alcohol resistance, so when used in applications where they come into contact with contents containing water and/or alcohol, they may become cloudy. This development is further accelerated at high temperatures, which has the disadvantage of significantly reducing commercial value.

Conventionally, as a method for improving water resistance, a method has been proposed in which octyl acrylate is added as a component of the monomer mixture and polymerized (Japanese Patent Publication No. 4921105), but although these methods improve water resistance, No alcoholic improvement was observed.

In other words, the improvement of the alcohol resistance of acrylonitrile resins is not achieved by simply imparting water resistance to the acrylonitrile polymer, but rather in addition to water resistance. It is necessary to impart alcohol resistance properties.

In addition, the graft-blend type acrylonitrile resin has the practical drop strength (
The drop strength (hereinafter referred to as impact strength) when filled with contents is low and unsatisfactory for practical purposes.

Furthermore, this resin has unsatisfactory points in terms of transparency, color tone, and processability (flow during molding processing), and improvement thereof is desired. Therefore, an object of the present invention is to provide a gas-impermeable acrylonitrile resin composition that has alcohol resistance, excellent impact resistance such as practical drop strength, and transparency, and has improved color tone and additivity. It's about doing.

The acrylonitrile resin composition of the present invention that achieves the object of the present invention comprises the following components (A) and (8):
This is a mixture obtained by mixing the diene rubber-like polymer in the obtained composition [(A) former B) so that the content thereof is 3 to 20% by weight.

Component (A): 60 to 90% by weight of acrylonitrile, preferably 65 to 85% by weight, and 1 to 35% by weight of at least one selected from acrylic acid alkyl esters and methacrylic acid alkyl esters having an alkyl group having 1 to 6 carbon atoms. Preferably 5 to 30% by weight and 0.5 methacrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms.
A resinous copolymer obtained by polymerizing a monomer mixture comprising 1 to 15% by weight, preferably 1 to 10% by weight.

Seishu B): 30 parts by weight of acrylonitrile in the presence of 40 to 60 parts by weight of a diene-based rubbery polymer consisting of 50% by weight or more of conjugated diene units and 50% by weight or less of acrylonitrile units.
~60% by weight, preferably 35-55% by weight and 1 carbon number
40 to 70% by weight, preferably 45 to 65% by weight of at least one selected from acrylic acid alkyl esters and methacrylic acid alkyl esters having ~6 alkyl groups, and methacrylic acid having an alkyl group having 12 to 18 carbon atoms. Alkyl ester 0-15% by weight, preferably O-
A graft copolymer obtained by polymerizing 40 to 60 parts by weight of a monomer mixture consisting of 10% by weight. In the present invention, a methacrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms, which is one of the monomers constituting the resinous copolymer (self), is added to the graph doplet type acrylonitrile resin composition. It is an important component essential for imparting alcohol resistance and improving transparency.

According to the light transmittance test, the effect of the methacrylic acid alkyl ester on alcohol resistance improves as the number of carbon atoms in the alkyl group increases from 12 to 18 carbon atoms, but the sleep opening test shows that there is no difference in the degree. is difficult to judge. When the methacrylic acid alkyl ester is replaced with an acrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms, no improvement in alcohol resistance is observed and transparency is reduced. Regarding the amount of methacrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms, its effect is recognized at 0.5% by weight or more based on the total monomers for producing the component, and the amount As the amount increases, the alcohol resistance further improves, but even if 15% by weight or more is used, the degree of improvement reaches saturation, and peeling phenomena occur in the melt-molded product. From these facts, Cl
The proportion of methacrylic acid alkyl ester having 2 to 18 alkyl groups is 0.5 to 15% by weight, preferably 1 to 15% by weight.
It is preferably 10% by weight, more preferably 1 to 5% by weight. The alcohol resistance and transparency of the composition of the present invention have a carbon number of 12 to 1.
Great improvements can be made by incorporating a methacrylic acid alkyl ester having eight alkyl groups as a constituent component of the resinous copolymer (4), but when it is desired to further improve such properties, grafting When producing the copolymer (B), the methacrylic acid alkyl ester is added as a graft monomer component.

The amount added is up to 15% by weight based on the total graft monomer.
Preferably up to 10% by weight and more preferably from 1 to 5% by weight
shall be. If 15% by weight or more is used, the effect reaches saturation and is also disadvantageous from an economical point of view.

The remarkable improvement effect of the impact resistance, transparency, and processability of the graft-blend type acrylonitrile resin composition composed of component (A) and component (g) according to the present invention is due to the fact that the graft This can be achieved by producing the copolymer (B) using a specific method as described above.

That is, the amount of acrylonitrile used in the total graft monomer is 30 to 60% by weight, preferably 35 to 5% by weight. On the other hand, when a large amount of acrylonitrile is used (60 to 70% by weight or more) as in a known method, the impact resistance decreases, and the yellowing of the molded product increases and the color tone decreases. . If it is less than 30% by weight, the impact resistance will be reduced and the surface gloss of the molded product will be poor, and in either case, it is impractical.

Further, the amount of acrylic acid alkyl ester having an alkyl group having 1 to 6 carbon atoms is 40 to 70% by weight, preferably 45 to 65% by weight, and the reason for this is the same as described regarding the amount of acrylonitrile used. corresponds to

In addition, the ratio of the diene rubber-like polymer and the Gura monomer to be graft-polymerized thereto is 40-60:60-40.
(parts by weight) improves impact resistance.

When the proportion of the rubber-like polymer is 60 parts by weight or more, a decrease in impact resistance and a decrease in surface gloss of the molded product is observed;
When the amount is less than 1 part by weight, disadvantages arise such as a decrease in impact resistance, a decrease in processability (deterioration in flow characteristics due to an increase in viscosity during molding), and an accompanying increase in yellowing of the molded product. The mixing ratio of component A) and component I3) is (A)+
The composition consisting of (B) contains 3 to 3 diene-based rubbery polymers.
The proportion is 20% by weight, preferably 5 to 20% by weight.

Even if the proportion of the diene-based rubbery polymer exceeds 20% by weight, the improvement in impact resistance reaches saturation and gas impermeability decreases, which is not preferable. The diene-based rubbery copolymer used in the present invention contains 50% by weight or more of conjugated diene units such as butadiene or isoprene, preferably 70 to 100% by weight.
It is a diene rubbery copolymer comprising more preferably 70 to 95 weight % and less than 50 weight % of acrylonitrile units, preferably 0 to 30 weight %, and more preferably 5 to 30 weight %.

If the amount of acrylonitrile used is 50% by weight or more, the impact resistance of the resulting resin composition will decrease and yellowing of the molded article will increase, which is not preferable. Further, as the diene-based rubbery copolymer, one having a low glass transition point (Tg) is preferable in order to improve the impact resistance of the resin composition. Examples of the acrylic acid alkyl ester and methacrylic acid alkyl ester having an alkyl group having 1 to 6 carbon atoms used in the present invention include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, and methacrylic acid. Examples include ethyl, propyl methacrylate, butyl methacrylate.

Examples of the methacrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms include lauryl methacrylate, dodecyl methacrylate, myristyl methacrylate, cetyl methacrylate, and stearyl methacrylate. The resinous copolymer (A) can be produced by the known bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization methods, etc., but it is preferable to use the emulsion polymerization method (.

Graft copolymerization method B) & zeta It can be produced by using a diene rubber-like polymer in the form of an emulsion latex, adding a graft monomer, and carrying out graft polymerization according to a known method. Polymerization initiators used in the production of Seishu A and component (B) of the present invention include water-soluble initiators such as potassium persulfate, ammonium persulfate, and hydrogen peroxide, azobisisobutyronitrile, benzoyl peroxide, A redox initiator system using oil-soluble initiators such as tert-butyl peroxyhybalate alone or in combination, or in combination with these initiators is used. Further, these polymerizations can be carried out by a batch method in which the monomer mixture and other components involved in the copolymerization are added continuously or intermittently. The resinous copolymer powder and the graft copolymer 03) may be mixed by either dry blending or latex blending. The present invention will be explained below by way of examples.

All parts and percentages in the examples are based on weight unless otherwise specified. Example 1 (1) Production of diene-based rubbery polymer latex Polymerization recipe for rubbery polymer All of the above polymerization recipe except CHP was charged into an autoclave and the temperature of the reaction system was adjusted to 5°C under a nitrogen atmosphere. Later, CHP was added to the system for 20
The reaction was completed while stirring for a period of time (the conversion rate of the monomer mixture was 97%).

), a good acrylonitrile-butadiene rubbery copolymer (NBR) latex was obtained. When observed using an electron microscope, the rubbery polymer in the latex was found to be uniformly sized particles with an average particle size of 0.1 μm.

This acrylonitrile-butadiene rubbery copolymer latex is used in the preparation of graft copolymers in the following examples. 1) Production of resinous polymer 100 parts of the monomer mixture shown in Table 1, 1.5 parts of n-dodecyl mercaptan, 0.8 parts of sodium lauryl sulfate, 0.2 parts of anhydrous sodium pyrophosphate, potassium persulfate. 0.08 parts and 200 parts of water were placed in an autoclave, and polymerization was carried out at 55° C. for 16 hours while stirring in a nitrogen atmosphere to obtain a good resinous copolymer latex.

The final conversion of the monomer mixture is shown in Table 1. (III)
Preparation of Graft Copolymer Vermilion B) 100 parts of the monomer mixture shown in Table 2, 100 parts of the acrylonitrile-butadiene rubbery copolymer (i) (as solid content in the latex), 0. 3 parts, sodium lauryl sulfate 0.8 parts, anhydrous pyrroline, soda 0.2 parts potassium maprsulfate 0.08 parts, water 6
00 parts were charged into an autoclave, and polymerization was carried out at 55° C. for 16 hours while stirring under a nitrogen atmosphere to obtain a good graft copolymer latex.

The final conversion of the monomer mixture is shown in Table 2. Next, the resinous polymer (゛) described above and the latex (1゛) were added.
Graft copolymer B) latexes were mixed in the combinations shown in Table 3 so that the content of the rubbery copolymer in the resulting resin composition was 13% by weight, and this mixed latex was The polymer was salted out with a 4% aluminum sulfate aqueous solution, washed separately with water, and then dried at 60° C. for 48 hours to obtain a white powder polymer.

The thus obtained white powdery polymer was melt-kneaded for 3 minutes with a heated roll at 160°C to make a roll sheet, and this rolled sheet was preheated with a 170°C heated press for 5 minutes, pressurized for 5 minutes, and then cooled. We made a 1m77J sheet with a glossy surface.

Next, the alcohol resistance of each press sheet was tested using the following method. Chemical resistance test ASTM D543-67
The sheet was immersed for 30 hours in a 50% ethyl alcohol aqueous solution adjusted to 50°C based on the JIS standard.
Parallel light transmittance was measured based on the K67l4 test method.

In order to see the rate of decrease in parallel light transmittance before and after dipping, the ratio of parallel light transmittance before and after dipping was expressed as a percentage.

These results are summarized in Table 3. Example 1 of the present invention
It can be seen that sheet No. 2 has good initial transparency and a large light transmittance value after immersion in alcohol, indicating that it has excellent alcohol resistance.

Note that the immersed sheets of Invention Example &1 and Black 2 are both transparent to the naked eye, and the difference cannot be determined. However, comparative example f). In Sample No. 5, some white turbidity was observed in the sheet before immersion, and in addition, the sheets of Comparative Examples Black 1, 2, 3, 4, and 5 became clearly cloudy after immersion, and the transparency was significantly impaired.
Example 2 The resinous polymer (A) of (4) listed in Example 1 and (11
Example 1 The graft copolymer (1) latex of i) was mixed in the combination shown in Table 4 so that the content of the rubbery copolymer in the resulting resin composition was 8%.
Salting out, drying, roll sheets, and press sheets were made using the same operations and measurement methods as above, and alcohol resistance tests were conducted.

The results are summarized in Table 4. Example of the present invention Jff).
It can be seen that sheet No. 3 had good initial transparency and a large light transmittance value after immersion in alcohol, indicating that it had excellent alcohol resistance.

However, the sheets of Comparative Examples Black 6 and 7 after immersion became clearly cloudy and their transparency was significantly impaired. Example 3 100 parts of the monomer mixture shown in Table 5, the parts of the acrylonitrile-butadiene rubbery polymer of Example 1 (1) (as solid content in the latex) shown in Table 5, t-dodecyl mercaptan 0 .3 parts, however, when producing B-1 (7), 1.5 parts of n-dotesyl mercaptan, 0.8 parts of sodium lauryl sulfate, 0.2 parts of anhydrous sodium pyrophosphate, 0.08 parts of potassium persulfate, and water. The quantities shown in Table 5 were charged into an autoclave, and polymerization was carried out at 55° C. for 16 hours with stirring under a nitrogen atmosphere to obtain a good graft copolymer latex.

The final conversion of the monomer mixture is shown in Table 5. Then, the above graft copolymer (B) q-depleted B-(4), B-(5
), B-(6) each latex and the graft copolymer listed in Example 1 (11f) B) latex and Example 1 (I
Using the resinous polymer A latex listed in i), the combinations shown in Table 6 were adjusted and mixed so that the content of the rubbery copolymer in the resulting resin composition was 13% by weight,
In addition, the (4)B-(7) latex of the above graft copolymer (B) was used alone, and each of these latexes was added at a concentration of 0.4
The polymer was salted out with a % aluminum sulfate aqueous solution, washed separately with water, and then dried at 60° C. for 48 hours to obtain a white powder polymer.

Using this, the following physical properties were investigated. The evaluation method was as follows, and the results are summarized in Table 6. Impact resistance: Pellets were made from a white powdery polymer using an extrusion molding machine heated to 180°C, and blow pins of 300 cc were made from the pellets using a blow molding machine heated to 190°C. Measure the weight of the blow pin, then fill the blow pin with water 3007 at 5℃, seal it, leave it at 5℃ for 1 hour, drop it perpendicular to the flat surface of the iron plate, and measure the height at which 50% of the blow pin breaks. I asked for it. Processability: 200k9/200k using the above pellets using a Koka type flow tester.
The relationship between temperature and viscosity is investigated by the heating method under the load of Cd, and compared to the temperature at which the melt viscosity is 105 poise.

Color tone: Cut the above-mentioned blow pin open, preheat for 5 minutes with a 17"C heating press, pressurize for 5 minutes, and then cool to create a transparent 3 mm press sheet with a glossy surface. The color tone was determined using the JIS K7lO3 reflected light method. The yellowness was measured using an automatic colorimeter.

Gas impermeability: A 0.02 mu thin film was prepared by the inflation method, and the oxygen permeability was measured based on the test method of ASTM D1434-63.

As shown in Table 6, 5 of the blow pins of each sample of the present invention
The height of 0% failure is high and the impact strength is clearly excellent, whereas the comparative and reference samples are low and have poor practicality.
oAlso, the melt viscosity of the graph doplet type resin is clearly lower than that of the graft type resin (reference example), and the processability is superior, but on the other hand, as seen in Comparative Example & 9, the graft monomer content of the graft copolymer If the proportion of the solid mixture increases, the melt viscosity will increase, which is undesirable.

Regarding the color tone of the molded product, as shown in Comparative Examples Black 1 and 8 and Reference Example, the yellowness value increases as the amount of acrylonitrile in the monomer mixture to be graft copolymerized increases, and the commercial value increases. decreases.

Regarding oxygen permeability, generally 10-11CC (71L
/Cdsec? If it is below Hg, it is said that the oxygen permeability is low, so the sample of the present invention poses no practical problem.

Example 4 The monomer components in the resinous polymer A-(1) prepared in Example 1 were converted into acrylonitrile/hexyl methacrylate/
Polymer A-(7) prepared in the same manner as A-(1) except that lauryl methacrylate (75/20/5) was used as A-(7).
The same experiment as in Inventive Example 1 was conducted (Inventive Example 7) except that -(1) was used instead.

The results are shown in Table 7. Example 5 Graft copolymer B-(1) prepared in Example 1 was prepared in the same manner as B-(1) except that the graft monomer component was acrylonitrile/butyl methacrylate (50/50). An experiment similar to Inventive Example 1 was conducted (Inventive Example 8) except that Polymer B-(8) was used in place of B-(1).

Claims (1)

[Claims] 1 60-90% by weight of acrylonitrile and 1-6 carbon atoms
1 to 35% by weight of at least one selected from acrylic acid alkyl esters and methacrylic acid alkyl esters having an alkyl group of A resinous copolymer (A) obtained by polymerizing a monomer mixture consisting of 40 to 60 parts by weight of a diene-based rubbery polymer consisting of 50% by weight or more of conjugated diene units and 50% by weight or less of acrylonitrile units. 30 to 60% by weight of acrylonitrile, 40 to 70% by weight of at least one selected from acrylic acid alkyl esters and methacrylic acid alkyl esters having an alkyl group having 1 to 6 carbon atoms, and alkyl groups having 12 to 18 carbon atoms. A graft copolymer (B) obtained by polymerizing 40 to 60 parts by weight of a monomer mixture consisting of 0 to 15% by weight of an alkyl methacrylate having an alkyl group is added to the diene system in the resulting composition. A gas-impermeable acrylonitrile resin composition having excellent alcohol resistance, impact resistance, transparency, color tone and processability, obtained by mixing a rubbery polymer in a content of 3 to 20% by weight. 2 Acrylonitrile 65-85% by weight and carbon number 1-6
5 to 30% by weight of at least one selected from acrylic acid alkyl esters and methacrylic acid alkyl esters having alkyl groups of
and a resinous polymer (A) obtained by polymerizing a monomer mixture consisting of 40 to 60 parts by weight of a diene-based rubbery polymer consisting of 50% by weight or more of conjugated diene units and 50% by weight or less of acrylonitrile units. Acrylonitrile in the presence of 35~
55% by weight, 45-65% by weight of at least one selected from acrylic acid alkyl esters having an alkyl group having 1 to 6 carbon atoms and methacrylic acid alkyl esters having an alkyl group having 12 to 18 carbon atoms, and an alkyl methacrylate having an alkyl group having 12 to 18 carbon atoms. Monomer mixture 4 consisting of 0 to 10% by weight of ester
A graft copolymer (B) obtained by polymerizing 0 to 60 parts by weight is mixed so that the content of the diene rubbery polymer in the resulting composition is 5 to 20% by weight. The resulting resin composition according to claim 1. 3. The resin composition according to claim 1 or 2, wherein the acrylic acid alkyl ester is methyl acrylate. 4. The resin composition according to claim 1, 2 or 3, wherein the methacrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms is lauryl methacrylate. 5. The resin composition according to claim 1, 2 or 3, wherein the methacrylic acid alkyl ester having an alkyl group having 12 to 18 carbon atoms is stearyl methacrylate. 6. The resin composition according to claim 1, 2, 3, 4, or 5, wherein the conjugated diene unit is butadiene. 7. Claims 1 and 2, wherein the diene rubbery polymer is an acrylonitrile-butadiene rubbery copolymer.
3. The resin composition according to item 3, item 4, or item 5.